Some light illuminating device such as a linear light illuminating device comprises a lengthy LED board on which multiple LEDs are loaded, a housing that houses the LED board, and a heat conductive member that is arranged between the LED board and the housing and that conducts heat produced by the LED board away to a radiation fin arranged on the housing.
Conventionally, as a method for securing the LED board to the housing, it is known to press both end parts of a longitudinal direction of the LED board toward the housing side through the heat conductive member.
However, in a case that the heat conductive member is made of a material such as silicon rubber or the like having viscoelasticity, with the above-mentioned arrangement, wherein the both end parts of the longitudinal direction of the LED board are pressed so as to secure the LED board, the LED warps and therefore the LED board is prevented from being tightly attached to the heat conductive member. As a result, there are problems in that not only the heat conductive efficiency is decreased, but also each light irradiating direction of the LEDs is misaligned.
In addition, LEDs that are known to be loadable on the LED board are an LED of a bullet-shaped type and an LED of a surface mounting type. In a case that an LED of the surface mounting type is used, as shown in the patent document 1, it is necessary to arrange a lens part member separately from the LED and thus the lens part member is secured to the housing.
However, with this arrangement, it is necessary to secure the LED board and the lens part member respectively to the housing, which requires positioning of the LED and the lens part member. As a result, there is a problem that workability is extremely low.